Hi,
Filebot AMC (across earlier versions of Filebot and now v4.9.1) has not been matching television show titles using TheTVDB for several months, instead all these files are processed into the "Unsorted" folder. Both music and movies (which don't use TheTVDB obviously) are being processing correctly. Are you aware of any issues with TheTVDB in AMC? Any advice on how I can fix this?

Different calls with different formats suggests you're trying to debug your complex custom format on the command-line. This is painful and ineffective. Use the GUI instead for prototyping and testing your custom format.

The next step is to dissect your complex custom format in the Format Editor to figure it out:

The first obvious issue is that this is wrong, within the Groovy context:

Any further debugging I will leave to you. Just divide and conquer. Test each component by itself. And remember to differentiate between Groovy context, and FileBot Format context, {...} can mean different things in different contexts.